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Superconducting DNA

Posted by michael on from the short-circuit dept.

Mr_Dyqik writes "Alik Kasumov of the Laboratoire de Physique des Solides in France and co-workers have shown that DNA molecules act as ohmic conductors above 1K and that below this temperature they can superconduct. This could allow the creation of self assembling superconducting circuits. (A Y Kasumov et al 2001 Science 291 280). The story is on PhysicsWeb."

1 of 70 comments (clear)

  1. Superconductors in a nutshell. by zCyl · · Score: 5

    While interesting in an academic sense, such a discovery is rather trivial in a practical sense. Superconductivity itself has a number of astonishing uses that can sometimes look like magic, but they're only useful when we can get them to occur at useful temperatures. Unfortunately, cooling something to 1K will require something along the lines of laser cooling in order to achieve, and this turns out to not be very practical. Superconductors with a very low critical temperature cannot conduct much current before they exceed their critical energy level and "go normal".

    Useful superconductors are more in the line of HTC's, high temperature superconductors. The simplest of these are the superconductors that work when cooled to the order of 70 degrees Kelvin (-200C) by liquid nitrogen (which is cheaper than beer). If I recall correctly, the highest published HTC was around 175K, which is only 100 degrees below freezing. I've heard rumors of higher temperature superconductors, but haven't seen any referreed publications of results yet. Keep your eyes peeled, we'll see room-temperature superconductors within the lifetimes of most slashdotters.

    To be fair to lower temperature superconductors, I believe the maglev train in Japan uses a lower temperature superconductor cooled by liquid helium, which is somewhere down on the order of 10K.

    Superconductors aren't too useful for their property of not conducting current, since they have a critical maximum current level anyway. They are mostly used for their diamagnetic properties (they repel magnetic flux lines). This is the basis for how an MRI works, or for how super-fast magnetic trains work.